McCarthy has revealed the Trinidad and Tobago international midfielder, 34, is a hugely influential member of the Championship side, who have all but secured their safety with four wins from their last seven games.
Edwards has missed just three league fixtures for the Tractor Boys this campaign and after recent winning goals against Bolton and Derby is viewed by McCarthy as a model professional for the club's youngsters.
He told the East Anglian Daily Times: "Carlos is a really good example to any young player in the way he conducts himself and to have the levels of fitness that he has.
"He comes in with a smile on his face, trains well every day and is a good person to have around the club. That's why he is captain.
"He's not demonstrative but works in a calm and collected way. He does his job properly and everyone respects that."